app.py

import os
import time
import streamlit as st
from transformers import pipeline
from pydub import AudioSegment
import tempfile
import torch
from datasets import load_dataset
import jiwer
import librosa  
import soundfile

# Page configuration
st.set_page_config(page_title="Audio-to-Text with Grammar Check", page_icon="🎤", layout="wide")

# Model configurations (three ASR models)
MODELS = {
    "automatic-speech-recognition": {
        "whisper-tiny": "openai/whisper-tiny",
        "whisper-small": "openai/whisper-small",
        "whisper-base": "openai/whisper-base"
    },
    "text2text-generation": {
        "flan-t5-base": "pszemraj/grammar-synthesis-small"
    }
}

# Cached model loading
@st.cache_resource
def load_model(model_key, task):
    device = "cuda" if torch.cuda.is_available() else "cpu"
    with st.spinner(f"Loading {model_key} model..."):
        return pipeline(task, model=MODELS[task][model_key], device=device)

def convert_audio_to_wav(audio_file):
    """Convert uploaded audio to WAV format"""
    try:
        with tempfile.NamedTemporaryFile(suffix=".wav", delete=False) as tmp_file:
            audio = AudioSegment.from_file(audio_file)
            audio.export(tmp_file.name, format="wav")
            return tmp_file.name
    except Exception as e:
        st.error(f"Audio conversion failed: {str(e)}")
        return None

def evaluate_asr_accuracy(transcription, reference):
    """Calculate WER and CER accuracy"""
    ref_processed = reference.lower().strip()
    hyp_processed = transcription.lower().strip()
    
    if not ref_processed:
        return 0.0, 0.0
    
    wer = jiwer.wer(ref_processed, hyp_processed)
    cer = jiwer.cer(ref_processed, hyp_processed)
    
    return  wer,  cer

# Cached dataset loading with audio decoding
@st.cache_data(show_spinner=False)
def load_cached_dataset(num_samples=1):
    st.info("Loading dataset...")
    try:
        dataset = load_dataset(
            "librispeech_asr", 
            "clean", 
            split="test", 
            streaming=True, 
            trust_remote_code=True
        ).take(num_samples)
        return [sample for sample in dataset]
    except Exception as e:
        st.error(f"Dataset loading failed: {str(e)}")
        return None

def main():
    st.title("🎤 Audio Grammar Evaluation System for Language Learners")
    
    # Session state for persisting results
    if "transcription" not in st.session_state:
        st.session_state.transcription = ""
    if "grammar_feedback" not in st.session_state:
        st.session_state.grammar_feedback = ""

    # Audio processing tab
    tab1, tab2 = st.tabs(["Audio Processor", "Model Evaluator"])
    
    with tab1:
        st.subheader("Upload & Process Audio")
        audio_file = st.file_uploader("Upload audio file", type=["mp3", "wav", "ogg", "m4a"])
        
        if audio_file:
            st.audio(audio_file, format="audio/wav")
            wav_path = convert_audio_to_wav(audio_file)
            
            if wav_path:
                asr_model = load_model("whisper-tiny", "automatic-speech-recognition")
                
                with st.spinner("Generating transcription..."):
                    transcription = asr_model(wav_path)["text"]
                    st.session_state.transcription = transcription
                    st.text_area("Transcription Result", transcription, height=150)
                
                if st.session_state.transcription:
                    grammar_model = load_model("flan-t5-base", "text2text-generation")
                    with st.spinner("Checking grammar..."):
                        grammar_feedback = grammar_model(
                            f"Correct the grammar in: {transcription}"
                        )[0]["generated_text"]
                        st.session_state.grammar_feedback = grammar_feedback
                        st.success("Grammar Corrected Text:")
                        st.write(grammar_feedback)
                
                os.unlink(wav_path)

    with tab2:
        st.subheader("Triple Model Evaluation with Runtime")
        
        # Model selection
        model_options = list(MODELS["automatic-speech-recognition"].keys())
        model1, model2, model3 = st.columns(3)
        with model1:
            selected_model1 = st.selectbox("Select Model 1", model_options, index=0)
        with model2:
            selected_model2 = st.selectbox("Select Model 2", model_options, index=1)
        with model3:
            selected_model3 = st.selectbox("Select Model 3", model_options, index=2)
        
        if st.button("Run Triple Evaluation"):
            dataset = load_cached_dataset(num_samples=1)
            if not dataset:
                return
            
            # Load three models
            model1 = load_model(selected_model1, "automatic-speech-recognition")
            model2 = load_model(selected_model2, "automatic-speech-recognition")
            model3 = load_model(selected_model3, "automatic-speech-recognition")
            
            results = []
            total_runtime_model1 = 0.0
            total_runtime_model2 = 0.0
            total_runtime_model3 = 0.0
            
            for i, sample in enumerate(dataset):
                with st.spinner(f"Processing Sample..."):
                    audio_array = sample["audio"]["array"]
                    reference_text = sample["text"]
                    
                    # Evaluate Model 1
                    start_time = time.perf_counter()
                    transcription1 = model1(audio_array)["text"]
                    end_time = time.perf_counter()
                    runtime1 = end_time - start_time
                    total_runtime_model1 += runtime1
                    wer1, cer1 = evaluate_asr_accuracy(transcription1, reference_text)
                    
                    # Evaluate Model 2
                    start_time = time.perf_counter()
                    transcription2 = model2(audio_array)["text"]
                    end_time = time.perf_counter()
                    runtime2 = end_time - start_time
                    total_runtime_model2 += runtime2
                    wer2, cer2 = evaluate_asr_accuracy(transcription2, reference_text)
                    
                    # Evaluate Model 3
                    start_time = time.perf_counter()
                    transcription3 = model3(audio_array)["text"]
                    end_time = time.perf_counter()
                    runtime3 = end_time - start_time
                    total_runtime_model3 += runtime3
                    wer3, cer3 = evaluate_asr_accuracy(transcription3, reference_text)
                    
                    # Organize results
                    model1_result = {
                        "Model": selected_model1,
                        "Runtime": f"{runtime1:.4f}s",
                        "WER": f"{wer1*100:.2f}%",
                        "CER": f"{cer1*100:.2f}%"
                    }
                    model2_result = {
                        "Model": selected_model2,
                        "Runtime": f"{runtime2:.4f}s",
                        "WER": f"{wer2*100:.2f}%",
                        "CER": f"{cer2*100:.2f}%"
                    }
                    model3_result = {
                        "Model": selected_model3,
                        "Runtime": f"{runtime3:.4f}s",
                        "WER": f"{wer3*100:.2f}%",
                        "CER": f"{cer3*100:.2f}%"
                    }
                    results.extend([model1_result, model2_result, model3_result])
            
            # Display results
            st.subheader("Model Evaluation Results")
            st.table(results)
            

if __name__ == "__main__":
    main()